With the rapid development of automation technology and artificial intelligence, robots play an increasingly important role in the human environment. In recent years, service robots have undergone rapid development, with cleaning robots as the main application. The cleaning robots covers a wide range, and may be classified into industrial and domestic robots according to the International Federation of Robotics (IFR). Domestic floor cleaning robots (vacuum cleaners) have been growing rapidly in recent years, and have become the mainstream product in the market, with an annual output of more than 2.5 million units. It is estimated that the global production value of cleaning robots will grow by six times, from 300 million US dollars in 2007 to 1.8 billion US dollars in 2014, showing great development potential.
One consideration about cleaning robots is the cleaning performance, which varies with different designs of the brush and vacuum module. If only the vacuum module is used, a larger suction force is required for drawing heavy granular powder particles, resulting in increased power consumption and noises. In addition to the design using only the vacuum module, a design combining the brush module with the vacuum module also exists. The brush module is used for collecting and guiding granular powder particles, such as dust and dirt, to the suction hole of the vacuum module for enabling the same to be removed by suction. However, even with the help of the brush module, the vacuum cleaning devices that are currently available still can not operating with satisfactory cleaning performance while maintaining low power consumption and low noise.
There is a conventional automatic vacuum cleaner disclosed in U.S. Pat. No. 6,883,201, which is an autonomous floor-cleaning robot capable of executing a floor cleaning process primarily by the use of its brush module while using its vacuum module for assisting the sweeping operation of the brush module. In this autonomous floor-cleaning robot, the dust cartridge and the fan blower are modularized designed to be integrated at the rear of the robot, whereas the dust cartridge is designed to be inserted inside the housing of the autonomous floor-cleaning robot as a flat drawer. Moreover, in U.S. Pat. Pub. No. 20070157420, a robot cleaning system is disclosed, which includes a first cleaning unit, i.e. s robot cleaner, to perform an automatic cleaning process while moving by itself in an area to be cleaned, and a second cleaning unit, i.e. a manual cleaner, to perform manual cleaning while being coupled to the first cleaning unit as it is moved by a user in an area to be cleaned. The first cleaning unit has a dust outlet to deliver dust to the second cleaning unit when the first cleaning unit is coupled to the second cleaning unit via the dust outlet of the first cleaning unit, and thereby, the robot cleaning system is capable of removing dust and debris collected in a robot cleaner during manual cleaning without having to dismantle the robot cleaner. In addition, there is a dust collector for autonomous floor-cleaning device disclosed in U.S. Pat. Pub. No. 20070028574, which is a container mounted in the air flowing path inside an autonomous floor-cleaning device at a position located at the top of the autonomous floor-cleaning device. As the air flowing path is designed to be detachable from the fan blower of the autonomous floor-cleaning device, the whole dust collector can be removed from the autonomous floor-cleaning device from the top thereof.